Basically, all it does is enable you to search your phone contacts (all of them, including Facebook) by – a phone number. Simple as that. This functionality was not possible before Mango, and it is not possible in People hub either. I’ve been testing this app for a two months now and it has been useful on several occasions, especially for answering my wife’s questions like “somebody called me, do you know whose number is this…”.
I’ll let you know when the app becomes available on the Marketplace, and if anybody wants a XAP file, just let me know.
Update – application has passed the certification – download it here (direct Zune link). You will need Mango update for this.